CN109782200A - A kind of material measuring electromagnetic parameters method - Google Patents
A kind of material measuring electromagnetic parameters method Download PDFInfo
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- CN109782200A CN109782200A CN201811562646.3A CN201811562646A CN109782200A CN 109782200 A CN109782200 A CN 109782200A CN 201811562646 A CN201811562646 A CN 201811562646A CN 109782200 A CN109782200 A CN 109782200A
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Abstract
The invention discloses a kind of material measuring electromagnetic parameters methods, its step includes: the test 1) carried out to the nonstandard adapter 1 of nonstandard test fixture and nonstandard adapter 2 under T-shaped state, R state and L state, and the test data under three kinds of states is imported in fixture calibration module；2) fixture calibration module calculates the S parameter of nonstandard adapter 1 and nonstandard adapter 2 according to the test data；3) sample to be tested is put into the nonstandard test fixture to test, and obtained S parameter [S] _ measure is imported in fixture calibration module；4) S parameter comprising nonstandard adapter 1 and nonstandard adapter 2 in S parameter elimination [S] _ measure data is obtained according to step 2), obtains core data needed for calculating the electromagnetic parameter of the sample to be tested；5) electromagnetic parameter of the sample to be tested is calculated with TR method according to core data.The present invention effectively improves the testing efficiency and measuring accuracy of material electromagnetic parameter.
Description
Technical field
The present invention relates to a kind of material measuring electromagnetic parameters methods, belong to microwave engineering, material electromagnetic parameter test technology
Field.
Background technique
With the development of material science and microwave engineering, electromagnetic compatibility technology, the effect of electromagnetic wave transparent material, absorbing material becomes
It is very significant, therefore the measuring technique of research material electromagnetic parameter also becomes more and more important.To radio frequency absorbing material performance
Simulation calculation in, the measurement of dielectric constant and magnetic conductivity is crucial reasonably select material, device etc..
Related, the mesh of the measurement method of electromagnetic parameter and form, dispersion characteristics and the frequency range of application of measured material etc.
Preceding common measurement method both at home and abroad has Resonant-cavity Method, free-space Method, open circuit termination coaxial axis method and Transmission line method etc..Its
In, what is be widely used is " transmission/bounce technique " (Transmission/Reflection method), abbreviation TR method.Because
It has the characteristics that measure that bandwidth, measurement accuracy are high, are suitable for coaxial and Wave guide system and simple to operation.
The currently used electromagnetic parameters software based on TR method (i.e. transmission bounce technique) is surveyed according to Network Analyzer
The S parameter of examination directly calculates the electromagnetic parameter of specimen material, i.e. relative dielectric constant εrWith relative permeability μr.Existing software
Calculation process is as shown in Figure 1.
The shortcomings that existing scheme: existing software for calculation is only applicable to the test system using standard transmission line or waveguide fixture
System, if there is special-shaped or nonstandard structure to occur in test fixture, it will produced to the accuracy of the calculated result of material electromagnetic parameter
Raw larger impact.
Summary of the invention
The purpose of the present invention is to provide a kind of applicabilities, and wider, test fixture chooses more flexible measuring electromagnetic parameters side
Method.
The present invention increases nonstandard test fixture and fixture calibration method on the basis of existing test method.Fixture calibration
Method has used TRL calibration algorithm, for eliminating nonstandard adapter influence caused by measurement in test fixture.
The technical solution of the present invention is as follows:
A kind of material measuring electromagnetic parameters method, step include:
1) the nonstandard adapter 1 of nonstandard test fixture and nonstandard adapter 2 are carried out under T-shaped state, R state and L state
Test, and test data under three kinds of states is imported in fixture calibration module；Wherein, T-shaped state is direct-connected state, R shape
State is reflective condition, L state is extended line state；The nonstandard test fixture includes placing for placing the sample of material sample
Unit, nonstandard adapter 1 and nonstandard adapter 2；Sample placement unit is between nonstandard adapter 1 and nonstandard adapter 2；
2) fixture calibration module calculates the S parameter of nonstandard adapter 1 and nonstandard adapter 2 according to the test data,
That is [S] _ connector1 and [S] _ connector2；
3) sample to be tested is put into the nonstandard test fixture to test, and obtained S parameter [S] _ measure is imported
In fixture calibration module；
4) fixture calibration module is eliminated in [S] _ measure data according to [S] _ connector1, [S] _ connector2
S parameter information comprising nonstandard adapter 1 and nonstandard adapter 2 obtains core needed for calculating the electromagnetic parameter of the sample to be tested
Calculation is according to [S] _ dut；
5) TR method solves the electromagnetic parameter that module calculates the sample to be tested according to [S] _ dut.
Further, the interior side port of the nonstandard adapter 1, the interior side port of nonstandard adapter 2 and the sample are placed
Unit connection, the exterior side port of the nonstandard adapter 1, the exterior side port of nonstandard adapter 2 are used as test end face, for exporting
Test data.
Further, the sample placement unit includes the coaxial line being made of setting-out inner conductor and setting-out outer conductor, institute
Coaxial line is stated for being connected and fixed sample to be tested；The coaxial line is electrically connected with the nonstandard adapter 1, nonstandard adapter 2.
Further, the coaxial line passes through the interior side port of flange and the nonstandard adapter 1, nonstandard adapter 2
Interior side port is connected and fixed.
Further, the setting-out outer conductor is equipped with several positioning screw holes, will be to test sample for cooperating with set screw
Product are fixed between the setting-out outer conductor and the setting-out inner conductor.
Further, the interior side port of the nonstandard adapter 1, nonstandard adapter 2 interior side port be respectively with it is described
The matched coaxial configuration of coaxial line.
Further, one end of the setting-out inner conductor is equipped with locating slot, the other end is equipped with positioning protrusion, and described nonstandard turn
The interior side port of connector 1 is equipped with to be equipped with the matched locating slot of the positioning protrusion, the interior side port of the nonstandard adapter 2
With the matched positioning protrusion of locating slot of the setting-out inner conductor.
Further, the characteristic impedance of the coaxial line is 50 ohm.
Further, the exterior side port of the nonstandard adapter 1, nonstandard adapter 2 exterior side port be equipped with standard N-type connect
Mouthful.
Further, core data [S] _ dut method is calculated in the fixture calibration module are as follows: first by S parameter
[S] _ measure, [S] _ connector1 and [S] _ connector2 be converted to corresponding transmission matrix [T] _ measure,
[T] _ connector1 and [T] _ connector2；Then formula [T] _ dut=[T] _ connector1 is utilized-1*[T]_
measure-1* [T]_connector2-1Calculate transmission matrix [T] _ dut；Then transmission matrix [T] _ dut is converted into S
Parameter is to get having arrived core data [S] _ dut.
The hardware of a set of nonstandard test fixture constitutes usually as shown in Figure 2.From figure 2 it can be seen that by uniform transmission line
The S parameter (referred to as, [S] _ dut) for the sample placement unit that (off-standard size) and material sample are constituted, is for calculating material
The core data of electromagnetic parameter.But it is really contained in the S parameter (referred to as, [S] _ measure) that test end surface measurement obtains non-
Mark adapter 1 S parameter (referred to as, [S] _ connector1) and nonstandard adapter 2 S parameter (abbreviation, [S] _
Connector2 information).If the data of [S] _ measure is directly used to calculate material electromagnetic parameter, will certainly generate very
Big calculating error.
At test initial stage, if to nonstandard adapter 1 and nonstandard adapter 2 carry out T-shaped state (Through state, i.e., it is direct-connected
State), 3 kinds of surveys under R state (Reflect state, i.e. reflective condition) and L state (Line state, i.e. extended line state)
It tries (TRL state is as shown in Figure 3), and the test data under three state is imported in fixture calibration module, then fixture calibrating die
Block will calculate the S parameter of nonstandard adapter 1 and nonstandard adapter 2, i.e. and [S] _ connector1 and [S] _
connector2.The data of [S] _ connector1 and [S] _ connector2 are utilized, fixture calibration module will use De- embedding
Algorithm is eliminated [the S] _ connector1 for including in [S] _ measure data and [S] _ connector2 information, and then is counted
Core data [S] _ dut needed for calculating electromagnetic parameter.Software for calculation utilization [S] _ dut can accurately calculate the electromagnetism of material
Parameter.
The data handling procedure for the De- embedding algorithm that fixture calibration module uses is as shown in Figure 4.Firstly, known S is joined
Number [S] _ measure, [S] _ connector1 and [S] _ connector2 be converted to corresponding transmission matrix [T] _ measure,
[T] _ connector1 and [T] _ connector2.Then, be calculated with formula 1 out the transmission matrix [T] of device under test DUT _
Dut, wherein [T] _ connector1-1It is the inverse matrix of [T] _ connector1, [T] _ connector2-1Be [T] _
The inverse matrix of connector2.Finally, transmission matrix [T] _ dut is converted to S parameter to get core data [S] _ dut has been arrived.
[T] _ dut=[T] _ connector1-1*[T]_measure-1*[T]_connector2-1Formula (1)
Calculation process of the invention is as shown in Figure 5.
In above-mentioned calculating process, fixture calibration module can calculate the S parameter of nonstandard adapter.This can be used as this
One additional function of invention carries out the S parameter test of various nonstandard adapters.
In order to realize the TRL calibration algorithm in this set test method, the present invention devises a set of nonstandard test fixture, nonstandard
The specific structure of test fixture is as shown in Figure 6.Setting-out inner conductor and setting-out outer conductor constitute setting-out coaxial line, and material sample is put
It sets among setting-out inner conductor and setting-out outer conductor, set screw is screwed into positioning screw hole to fixed material sample in setting-out
Position in coaxial line.The outer diameter of setting-out inner conductor and the internal diameter of setting-out outer conductor can freely be chosen, but should protect as far as possible
The particular-trade impedance for demonstrate,proving setting-out coaxial line is 50 ohm.
Nonstandard adapter 1 and nonstandard adapter 2 are used to realize the transition of setting-out coaxial line to standard N-type interface, to guarantee
The N-type coaxial cable that standard can be used in vector network analyzer is tested.Nonstandard adapter 1 and nonstandard adapter 2 it is interior
Conductor is connect by screw thread with setting-out inner conductor, to realize the electrical contact of inner conductor.Nonstandard adapter 1 and nonstandard adapter 2
Outer conductor connect with setting-out outer conductor by locating flange, to realize the electrical contact of outer conductor.
This set test fixture is by flexible combination, three state needed for TRL calibration may be implemented, structure such as Fig. 7 institute
Show.As shown in Fig. 7 (a), nonstandard adapter 1 and nonstandard adapter 2 are docked, and the T-shaped state in Fig. 3 (a) can be realized.Such as Fig. 7 (b)
Known, nonstandard adapter 1 connects a short-circuit face with each comfortable terminal of nonstandard adapter 2, and the R shape in Fig. 3 (b) can be realized
State.As shown in Fig. 7 (c), nonstandard adapter 1 is connected with nonstandard adapter 2 by setting-out coaxial line, Fig. 3 (c) can be realized
In L state.
Compared with prior art, the positive effect of the present invention are as follows:
By introducing TRL calibration algorithm, solves the problems, such as that conventional test methodologies are limited to standard test fixture, widen
The optional range of test fixture, in order to cooperate the calibration algorithm present invention to devise a set of corresponding nonstandard test fixture；In addition, by
In by the lesser limitation of standard fixture size, very big difficulty usually is brought to the sample making course of material sample, and in the present invention
Nonstandard fixture can arbitrarily choose the size of inner and outer conductor in order to sample processing, so that the sample preparation of material sample be greatly reduced
Difficulty, and then effectively improve the testing efficiency and measuring accuracy of material electromagnetic parameter.
Detailed description of the invention
Fig. 1 is existing software calculation flow chart；
Fig. 2 is that nonstandard test fixture constitutes figure；
Fig. 3 is nonstandard adapter TRL state diagram, in which:
(a) it is T-shaped state, (b) is R state, (c) is L state；
Fig. 4 is De- embedding algorithm data process flow diagram；
Fig. 5 is the method for the present invention flow chart.
Fig. 6 is nonstandard test fixture structure chart, in which:
(a) it is front view (left side) and cross-sectional view (right side), (b) is side view；
Fig. 7 is nonstandard test fixture TRL state diagram, in which:
(a) it is T-shaped state, (b) is R state, (c) is L state.
Specific embodiment
Software for calculation of the invention can be write based on MATLAB.Software includes data transmission module, fixture calibration
Module, TR computing module and data are shown and memory module.Software for calculation is counted by network and vector network analyzer
According to communication, control and computing function are realized.The framework relationship of software for calculation and vector network analyzer and nonstandard test fixture
As shown in Fig. 6.
The operating method of software for calculation the following steps are included:
1) software for calculation is run, counted by the test frequency of system display interface setting vector network analyzer, measurement,
The length and thickness of sample of intermediate-frequency bandwidth and test fixture.
2) S parameter at this time is tested in the case where " T-shaped state " shown in nonstandard adapter 1 and 2 is in Fig. 3 (a)
([S] _ T) and the communication and storage for completing data.
3) S parameter at this time is tested in the case where " R state " shown in nonstandard adapter 1 and 2 is in Fig. 3 (b)
([S] _ R) and the communication and storage for completing data.
4) S parameter at this time is tested in the case where " L state " shown in nonstandard adapter 1 and 2 is in Fig. 3 (c)
([S] _ L) and the communication and storage for completing data.
5) sample to be tested is mounted in nonstandard fixture, is under test mode shown in Fig. 6 (a), test S ginseng at this time
Number ([S] _ measure) and the communication and storage for completing data.
6) software first with [S] _ T, [S] _ R and [S] _ L calculate the S parameter [S] of nonstandard adapter 1 and 2 _
Connector1 and [S] _ connector2.Then using De- embedding algorithm eliminate [S] _ measure in include [S] _
Connector1 and [S] _ connector2 information, obtain core data [S] _ dut.Finally [S] _ dut is used to calculate sample
The electromagnetic parameter of material, i.e. relative dielectric constant εrWith relative permeability μr。
In conclusion being not intended to limit the scope of the present invention the above is only preferable implementation method of the invention.It is all
Within the spirit and principles in the present invention, any modification, equivalent substitution, improvement and etc. done should be included in guarantor of the invention
Within the scope of shield.
Claims (10)
1. a kind of material measuring electromagnetic parameters method, step include:
1) survey under T-shaped state, R state and L state is carried out to the nonstandard adapter 1 of nonstandard test fixture and nonstandard adapter 2
Examination, and the test data under three kinds of states is imported in fixture calibration module；Wherein, T-shaped state is direct-connected state, R state is
Reflective condition, L state are extended line state；The nonstandard test fixture includes placing list for placing the sample of material sample
Member, nonstandard adapter 1 and nonstandard adapter 2；Sample placement unit is between nonstandard adapter 1 and nonstandard adapter 2；
2) fixture calibration module calculates the S parameter of nonstandard adapter 1 and nonstandard adapter 2 according to the test data, i.e.,
[S] _ connector1 and [S] _ connector2；
3) sample to be tested is put into the nonstandard test fixture to test, and obtained S parameter [S] _ measure is imported into fixture
In calibration module；
4) fixture calibration module is according to [S] _ connector1, [S] _ connector2, eliminates in [S] _ measure data and includes
The S parameter information of nonstandard adapter 1 and nonstandard adapter 2 obtains core number needed for calculating the electromagnetic parameter of the sample to be tested
According to [S] _ dut；
5) TR method solves the electromagnetic parameter that module calculates the sample to be tested according to [S] _ dut.
2. the method as described in claim 1, which is characterized in that interior side port, the nonstandard adapter 2 of the nonstandard adapter 1
Interior side port connect with the sample placement unit, the outboard end of the exterior side port of the nonstandard adapter 1, nonstandard adapter 2
Mouth is as test end face, for outputing test data.
3. method according to claim 2, which is characterized in that the sample placement unit includes by setting-out inner conductor and setting-out
The coaxial line that outer conductor is constituted, the coaxial line is for being connected and fixed sample to be tested；The coaxial line and the nonstandard adapter
1, nonstandard adapter 2 is electrically connected.
4. method as claimed in claim 3, which is characterized in that the coaxial line passes through flange and the nonstandard adapter 1
Interior side port, nonstandard adapter 2 interior side port be connected and fixed.
5. method as claimed in claim 3, which is characterized in that the setting-out outer conductor is equipped with several positioning screw holes, is used for
Cooperate with set screw and sample to be tested is fixed between the setting-out outer conductor and the setting-out inner conductor.
6. method as claimed in claim 3, which is characterized in that interior side port, the nonstandard adapter 2 of the nonstandard adapter 1
Interior side port be respectively and the matched coaxial configuration of the coaxial line.
7. the method as described in claim 3 or 6, which is characterized in that one end of the setting-out inner conductor is equipped with locating slot, another
End is equipped with positioning protrusion, the interior side port of the nonstandard adapter 1 be equipped with the matched locating slot of the positioning protrusion, it is described non-
The interior side port of adapter 2 is marked equipped with the matched positioning protrusion of locating slot with the setting-out inner conductor.
8. method as claimed in claim 3, which is characterized in that the characteristic impedance of the coaxial line is 50 ohm.
9. the method as described in claim 1, which is characterized in that exterior side port, the nonstandard adapter 2 of the nonstandard adapter 1
Exterior side port be equipped with standard N-type interface.
10. the method as described in claim 1, which is characterized in that the fixture calibration module be calculated core data [S] _
The method of dut are as follows: be first converted to S parameter [S] _ measure, [S] _ connector1 and [S] _ connector2 accordingly
Transmission matrix [T] _ measure, [T] _ connector1 and [T] _ connector2；Then using formula [T] _ dut=[T] _
connector1-1*[T]_measure-1*[T]_connector2-1Calculate transmission matrix [T] _ dut；Then by transmission matrix
[T] _ dut is converted to S parameter to get core data [S] _ dut has been arrived.
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| CN111157580A (en) * | 2020-01-10 | 2020-05-15 | 青岛兴仪电子设备有限责任公司 | High-temperature material electromagnetic parameter measurement system and method based on fixture de-embedding |
| CN113960510A (en) * | 2021-10-20 | 2022-01-21 | 北京环境特性研究所 | Coaxial annular material electromagnetic parameter testing seat and testing system testing method |
| CN114019197A (en) * | 2021-11-04 | 2022-02-08 | 苏州英嘉通半导体有限公司 | Load traction test fixture and de-embedding method |
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